An estimated 2.3 million construction workers work on scaffolds on a frequent basis. Protecting these workers could help prevent some 4,500 injuries and 50 deaths each year. A Bureau of Labor and Statistics study reported that 72% of workers injured in scaffold accidents attributed the accident to either the employee slipping or being struck by a falling object, or to the planking or support giving way. In response, the Occupational Health and Safety Administration’s (OSHA) Office of Construction Services has increased enforcement to prevent falls, including falls from scaffolds, on jobsites.
Builders have paid significant civil penalties for failing to ensure that their employees and trades are safe while working on scaffolds. U.S. employers spend approximately $90 million in workdays lost each year. Builders are also vulnerable to criminal penalties for jobsite fatalities; OSHA can issue willful violation citations and pursue statutory criminal penalties.
Here’s the good news: with some effort, builders can avoid these penalties. By checking scaffolds for key problems and having them corrected, it's possible to prevent worker injuries and fatalities.
Safe scaffold structure
To begin, the base section of a scaffold has to be stable. It's impossible to erect a safe scaffold if the base rests on items like barrels, boxes, loose bricks, or concrete blocks. These items are unstable and unlikely to provide a level foundation. Instead, scaffolds should be set on base plates, mud sills, or other items that provide an adequately firm foundation. The footings should be capable of supporting the loaded scaffold without settling or moving.
No matter how stable the base, the scaffold won't be safe if the work platform doesn't remain upright. As a general rule, a scaffold becomes unstable once its height reaches 4 times its width. If the scaffold is 4 times as high as its base is wide, outriggers should be installed to increase the scaffold’s width. An alternative to installing outriggers is to tie the scaffold to the structure under construction to keep it from tipping. If guys or ties are used, they should be installed on the horizontal member closest to the 4:1 width-to-height point. There should be a guy or tie every 20' up for scaffolds up to 3' wide and every 26' up for scaffolds more than 3' wide.
Safe scaffold rails and platforms
If the scaffold is 10' or higher above a lower level, top rails, midrails, and toeboards should be installed on all open sides of the scaffold platform. Rails should be made from 2x4s or the equivalent, and they should be 38" to 45" high. The rails should be able to withstand 200 pounds being thrown against them. Midrails should be halfway between the top rails and the platform. Toeboards should be able to withstand a force of at least 50 pounds, and they should be a minimum of 3 ½" high from the top edge to the level of the working surface.
Platforms should consist of undressed 2x10s that have been properly inspected and graded. The maximum allowable gap between planks is 1". The ends of the platforms must be cleated, be restrained, or extend at least 6" over the centerline of support. If a platform is more than 10' long, the ends shouldn’t extend over their supports more than 18". If a platform is 10' or fewer long, the ends shouldn't extend over their supports more than 12".
Safe scaffold access
All workers must be able to safely access any level of a scaffold that's 2' above or below an access point. They shouldn’t have to use the cross braces to enter or exit the platform. An attachable ladder or other means of access is required when the distance from one surface to the next is more than 2'. The ladder should be positioned so that the bottom rung isn't more than 2' above the worker’s starting point.
Safe scaffold use
OSHA states that scaffolds can be erected, moved, dismantled, or altered only under the supervision and direction of a "competent person." A "competent person" is someone who can identify hazards and is authorized to take prompt action to eliminate them. This individual should also inspect the scaffolds each day before workers use them and after anything happens to the scaffolds that could undermine their integrity.
It's important to not allow excessive debris and equipment to accumulate on or around the scaffold. Workers should have pulleys for pulling tools and equipment up and down the scaffold, leaving their hands free to climb access ladders. Don't allow anyone to work on scaffolds during storms or in high winds, and don’t allow anyone to move a scaffold while workers are on it unless it's been designed for that purpose. Repair, replace, or remove any damaged scaffold parts.
The payoff
The time and effort you spend on making sure scaffolds are safe pay off in the benefits you reap, including peace of mind, the health and safety of employees and trades on your jobsite, and the health of your business.
For more information about scaffold safety and other jobsite safety issues, visit OSHA, or check out BuildIQ University's online training courses, Jobsite Safety I and Jobsite Safety II.
